地下水对泥板岩强度软化的损伤力学分析

针对18层泥板岩处于龙滩水电站坝址进水口高边坡中这一特殊情况,深入探讨水-岩相互作用使其劣化的损伤机理。采用RMT-150B型岩石刚性伺服试验机,进行18层泥板岩不同吸水率情形下的单轴压缩试验。结果表明,泥板岩抗压强度的软化不仅与吸水率密切相关,而且还是吸水时间的函数。运用损伤力学理论分析地下水对岩石强度与变形的影响,初步建立与应力状态密切相关的岩石遇水损伤演化方程。结果表明,该理论能较好地描述岩石遇水损伤演化特征,从而为岩质边坡细雨入渗滑坡现象提供理论依据。

ANALYSIS ON STRENGTH SOFTENING OF ARGILLITE UNDER GROUNDWATER BY DAMAGE MECHANICS

For the special geologic condition of 18 layers of argillite located in highwall slope of the intake in Longtan Hydropower Station Project, a study on the damage mechanism of the water-rock interaction is carried out. A series of uniaxial compression tests of the 18 layers of argillite with different water content are conducted in Rock Mechanics Rigidity Servo Testing System(RMT-150B). The test results show that the softening of compressive strength of argillite is not only closely related to its water content, but the time of being soaked in water. The effects of groundwater on rock strength and deformation are analyzed by theories of damage mechanics. Through introducing the volumetric change caused by rock dilatancy to the damage variable, the evolution equation of damage of rock meeting with water is established, which is closely related to rock stress state. The experiments demonstrate that it can well describe rock damage features caused by water, and so it provides the theoretic basis for analyzing landslide phenomenon caused by rainfall infiltrating into rock masses.